There are known buttons, hooks, strings or snap closures, or zippers for closures or for locking two separate parts. However, these have each advantages and disadvantages. A lock closure using the attraction of a permanent magnet is known and used, but is constructed such that one of its component parts will only attract the other part opposite the first part. The device depends exclusively, or largely, upon the strength of the magnetic attraction for its capability and is relatively highly resistant to any external force that may be exerted at right angles to the end of the magnet. However, it is relatively less resistant to any force that may be applied laterally, so that the parts are apt to slide relative to each other. There is also known a magnetic lock closure which is provided with a hook for preventing such sliding, however, it cannot work as satisfactorily as the present invention.
The magnetic lock closure constructed according to this invention comprises two separate parts, at least one of which is made of a permanent magnet of a cylindrical or any other form having a hole or slit centrally therethrough for providing a female device. The female device also includes a piece of ferromagnetic material firmly secured to one end of the device, so that the force of the magnetic attraction is centered about the piece of ferromagnetic material. This piece may be provided with a rod portion which is inserted into the hole or slit. The magnetic attraction per unit area is thus remarkably increased and is capable of attracting the other part, or male device, which is also made of ferromagnetic material. The male device may be provided with a rod portion for insertion into the hole or slit. The male piece is thus prevented from sliding laterally, thus providing a reliable locking means.